This NSA document from January 2013 lists the codenames of those agency activities sufficiently sensitive to qualify as “exceptionally controlled information”: see the Intercept article Core Secrets: NSA Saboteurs in China and Germany, 10 October 2014.ah

This document outlines the NSA activities designated as “exceptionally controlled information”, which are only made known to a small number of US officials: see the Intercept article Core Secrets: NSA Saboteurs in China and Germany, 10 October 2014.

A classification guide on the NSA’s Project BULLRUN goals and capabilities in decryption: see the Guardian article Revealed: how US and UK spy agencies defeat internet privacy and security, 5 September 2013.